Body long, anteriorly and posteriorly tapered.
Prostomium heart-shaped, with the concave part posteriorly, with 5 antennae. Median antenna situated on a line between the anterior part of eyes, of similar shape and size as paired antennae. Eyes large, orange-red in living animals; both with lenses. Two ciliated nuchal organs postero-laterally.
Proboscis with few, minute, scattered papillae on distal part. Terminal ring of about sixteen papillae.
Segment 1 partly reduced dorsally. Tentacular cirri of segment 1 reaching segments 4-5. Dorsal tentacular cirri of segments 2 and 3 reaching about segments 8-10. Ventral tentacular cirri cylindrical or slightly flattened, reaching about segments 5-7, with small parapodial lobes fused to cirrophores, carrying about five chaetae. Dorsal cirri of median segments lanceolate, almost twice as long as broad. Parapodial lobes distinctly asymmetrical, upper part prolonged, digitate, with a rather large number of chaetae. Terminal end of chaetal shaft with large number of teeth, decreasing in size proximally. Blades long and slender. Ventral cirri of similar shape to dorsal cirri but smaller.
Pygidial cirri very long and slender. A minute median pygidial papilla present. Each segment dorsally and ventrally with two bands of cilia.
Up to 52 mm for 170 segments.
Living animals with reddish brown pigmentation, dense on prostomium, as transverse bands across dorsum on segments, and on dorsal cirri. Eyes red. Preserved animals dark brown, eyes brownish black.
Muddy sand or mixed bottoms with mud, sand, shells and stones. Known from about 25 to 500 m.
Barents Sea, Northern Atlantic, English Channel, northern North Sea, Skagerrak, Kattegat up to northern Öresund.